Jaguar and CFD

[desmo]

First off, hello to everyone. This is my first post on this forum. No I am not "Franklin"! ;-) Here goes:

At Silverstone Eddie Irvine commented that they had various aero mods the team
needed to test in the wind tunnel, but apparently the Swift tunnel the team must
share in California was occupied and that they couldn't use it for a couple of
weeks. Gary Anderson:

"That is a fact, we have done a CFD [computational fluid dynamics] solution and
we are making some bits on the basis of that. We should be able to test them in
the tunnel but we can't at the moment. I am a racer, so I am going to try them
anyhow. We shouldn't be in this situation.

"We are trying to find more wind tunnel time. We are competing against teams
which have their own wind tunnel facilities."

So they are resorting to CFD simulations which attept to mimic the behavior of the
airflow around the car using mathematical modeling.

"We have a full car 3-D CFD model. You can run things on that and get results from
it. We have to run it at Ford in the USA- even with their computing power it takes
30 hours to run the full models!"

The results garnered thus far argue to me that CFD is not yet a mature enough
technology to significantly supplant the wind tunnel as a development tool.
Whoever put Jaguar in this position must have thought that CFD could fill in the
gaps in tunnel testing caused by sharing wind tunnel facilities. Even Minardi(!) have
their own wind tunnel. Someday, soon perhaps even, CFD will mature into an
effective enough development tool to reduce the role of the wind tunnel.

In the meantime Jaguar is building a 49 million dollar state-of-the-art tunnel which
isn't expected to be completed for another 2 1/2 years. I hope, for his sake, Dario
has a long-term contract inked, 2001-2 are likely to be pretty ugly!

[angst]

Hmmmm.... putting two and two together, is this the real reason that the rules will not be changed to reduce the importance of aerodynamics, ie the huge investment teams have made in wind tunnels. Wouldn't make sense to make them only a periheral design tool would it?

[desmo]

The rationalisation most often cited for not substantially rewriting the technical regs is that it would place an unfair burden on the smaller-budget teams to embark on a new development path. The cynics cite the use of wings as advertising hoarding as the reason. I'm not sure I really buy either proposition.

The downside of CFD is rather uncertain quality of the results it generates thus far. The upside is that unlike a conventional wind tunnel which, as they're used by F1 teams, primarily measure the forces on the car generated by the airflow. CFD can potentially give insights into the nature of the airflow which aren't directly visible in a wind tunnel short of using techniques such as doppler laser anemometry which cannot easily measure the undercar flow or flow blocked from view by bodywork.

I doubt that computer modeling will ever completely supplant actual wind tunnel testing as you have to use a tunnel to test the validity of CFD results.

[Gerard]

Hi desmo, I can't answer your post because I'm a complet nono when it comes to technical matters.
But I'm sure you will get some answers from other members who know more about the subject.

All I want to say is welcome to 10 Tenths.

p.s. I had a look at your scrim-shawing website and wow, you're good man!

[desmo]

Thanks, Gerard that's nice of you to say.

Kurt